Moscow is “likely concerned” following a string of “unexplained explosions” heard in the now Russia-controlled city of Mariupol, according to UK intelligence.
The ministry of defence (MoD) explained in its daily briefing shared on Twitter that the Ukrainian city – seized by Russian forces in May 2022, after a long and bloody siege – now appears to be under fire.
Mariupol is in the Donetsk People’s Republic, in the south-east of Ukraine, a separatist state which was then illegally annexed by Russia in September.
Now, the MoD says there have been at least 14 explosions heard around the city since February 21, including at an ammo cache at the airport, fuel depots and steel works which are used as a military base by Russia.
Mariupol is at least 80 kilometres from the current frontline.
The MoD said: “Russia will likely be concerned that unexplained explosions are occurring in a zone it had probably previously assessed as beyond the range of routine Ukrainian strike capabilities.
“Although widely devastated earlier in the war, Mariupol is important to Russia because it is the largest city Russia captured in 2022 that it still controls and sits on a key logistics route.”
Last May, Russian defence ministry Sergei Shoigu announced “complete liberation” of the Azovstal steel plant in Mariupol, which was the last area of Ukrainian resistance.
The Ukrainian fighters who had been standing firm reportedly surrendered, and were taken as Russian prisoners.
At the time, it was a much-needed victory for Vladimir Putin, as his failure to seize the capital Kyiv within a matter of days, as initially promised, rocked morale in Russia and faith in the whole “special military operation”
Similarly unexplained explosions were previously been heard in the Russian-controlled peninsula of Crimea, a Ukrainian area which was seized back in 2014.
Although Ukraine did not openly take responsibility for the strikes, it was seen as a sign that the war dynamic was changing because the attacks were so far behind the frontline and Crimea is strategically important for Russia.
These latest explosions have also been reported near the one-year anniversary of the war, February 24.
Russia launched a symbolic new offensive to mark the occasion last week, particularly around the Ukrainian mining city of Vuhledar.
Ukrainian military has since released drone footage which claims to show Russian tanks and other armoured vehicles being blown up by mines or hit by Ukrainian air strikes on their way to the mining city.
The city Bakhmut has also been a central battleground in recent months, with Russian forces surrounding it since July.
Last week, the MoD also warned that Russia could claim a victory in Bakhmut, in the frontline Donetsk region to the east, “regardless of reality”.